JP2001151626A - Fine particles of acrylic copolymer for cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide fine particles of acrylic copolymer for cosmetics that can be more inexpensively produced than nylon powder, has good spreadability and adhesion to the skin, gives soft application feeling with no occurrence of the secondary coagulation. SOLUTION: A monomer mixture including (A) 15-60 wt.% of (meth)acrylate monomer giving a polymer with the glass transition point (Tg) of >=40 deg.C, (B) 20-70 wt.% of ethyl acrylate monomer and, when necessary, (C) 5-50 wt.% of polyfunctional vinyl monomer is subjected to suspension polymerization whereby fine particles of acrylic copolymer suitable for cosmetics are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to acrylic copolymer fine particles for cosmetics and cosmetics containing the same.

[0002]

2. Description of the Related Art As extenders used in cosmetics,
Natural mineral pigments such as talc, mica, kaolin, and sericite; and synthetic resin pigments such as nylon powder, polyethylene powder, polystyrene powder, silicone powder, and polymethyl methacrylate powder. Natural mineral pigments are irregular in particle diameter and shape, have a high specific gravity, and have relatively good adhesion to the skin, but have a strong roughness.
On the other hand, synthetic resin powders are generally spherical particles having a low specific gravity,
In particular, the fine particles obtained by the polymerization reaction have a uniform particle size distribution, and when blended in cosmetics because the particle surface is smooth, cosmetics with excellent extensibility can be obtained, but the disadvantage that adhesion to the skin is inferior is poor. is there. Nylon powder with the smoothest surface among the synthetic resin powders for cosmetics proposed so far has the softest feeling of use, is excellent in extensibility to the skin, and gives a lightly stretched cosmetic. . It also has good oil resistance, solvent resistance, especially alcohol resistance, and does not cause particle expansion or aggregation between particles at a low temperature of up to 50 ° C. But,
In the cosmetics manufacturing process, in the presence of oil additives and solvents, 90-
When heating and mixing at a temperature of 100 ° C. or higher are required, secondary aggregation or fusion between particles occurs due to a low melting point, and the desired cosmetic cannot be obtained. 12 used in cosmetics
Nylon powder is extremely expensive because it is produced by the unique ionic polymerization of laurolactam in paraffin. Furthermore, nylon powder also has the disadvantage that the preservative effect is lost because it absorbs the preservative ethylparaben and the like added to prevent decay of cosmetics. In contrast,
Polymethyl methacrylate powder is widely used because it is inexpensive, has little absorption of preservatives, and has excellent extensibility. However, the feeling of use is considerably inferior to nylon beads, and the adhesion to the skin is not good, probably because the extensibility is too good. In addition, they have poor oil resistance and solvent resistance, and cause aggregation and fusion between particles in the presence of an oily humectant or alcohol. Crosslinked polymethyl methacrylate monomer obtained by copolymerizing methyl methacrylate and polyfunctional vinyl monomer has improved oil resistance and solvent resistance, but the smoothness and soft feeling of use are further deteriorated, and it becomes powdery feeling,
Adhesion to the skin also decreases.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-temperature, soft-feeling material which is manufactured at a much lower cost than nylon powder, has comparable extensibility and adhesion to the skin as nylon powder, and has a soft feeling of use. An object of the present invention is to provide cosmetic acrylic copolymer fine particles that do not cause secondary aggregation between particles even in a solvent.

[0004]

SUMMARY OF THE INVENTION The present inventors have produced many kinds of poly (meth) acrylic resin powders based on many years of experience and knowledge of producing acrylic resin powders and used them for cosmetics. As a result of examining the performance of the above, a mixture containing (meth) acrylate monomer (A), ethyl acrylate (B) and polyfunctional vinyl monomer (C) having a glass transition temperature of 40 ° C. or higher as a monomer in a specific ratio was subjected to suspension copolymerization. The acrylic resin powder obtained by
It has been found that it has excellent elongation for cosmetics, adhesiveness to skin, soft feeling of use, heat resistance, etc., does not cause secondary aggregation, and exhibits various physical properties that are not inferior to nylon powder. The present invention was completed through further studies based on the findings. That is, the present invention relates to (1) a (meth) acrylate monomer (A) having a glass transition temperature (Tg) of 15 to 60% by weight of 40 ° C. or more, an ethyl acrylate monomer (B) of 20 to 70% by weight, and 0 to 50% by weight. Acrylic copolymer fine particles for cosmetics obtained by subjecting a monomer mixture containing a polyfunctional vinyl monomer (C) by weight to suspension polymerization, (2) glass transition temperature (T) of the acrylic copolymer
g) is 50 to 130 ° C., the acrylic copolymer fine particles for cosmetics according to the above (1), and (3) the fine particles of the copolymer have a particle size in the range of 1 to 40 μm and an average particle size of 4
(1) or (2) the cosmetic acrylic copolymer fine particles according to (1) or (2), and (4) the cosmetic comprising the cosmetic acrylic copolymer fine particles according to (1). .

[0005]

DETAILED DESCRIPTION OF THE INVENTION The (meth) acrylate monomer having a Tg of 40 ° C. or higher used in the present invention includes:
For example, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, isobornyl acrylate,
Hexachlorobutyl methacrylate and the like can be mentioned, and these can be used alone or in combination of two or more. The polyfunctional vinyl monomer is a cross-linking agent having two or more α, β-ethylenically unsaturated bonds in one molecule, for example, an aromatic divinyl monomer such as divinylbenzene; ethylene glycol di (meth) acrylate, propylene Alkylene glycol di (meth) acrylates such as glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate; diethylene glycol di (meth) acrylate triethylene glycol Polyalkylene glycol di (meth) such as di (meth) acrylate
Acrylates; polyols such as trimethylolpropane di (meth) acrylate and pentaerythritol tetra (meth) acrylate; poly (meth) acrylates; allyls such as allyl (meth) acrylate, allyl malate, diallyl fumarate, diallyl itaconate and triallyl isocyanurate Compounds can be exemplified. One or more of these polyfunctional vinyl monomers can be used.

In the present invention, the compounding weight% of the (meth) acrylate monomer (A) having a Tg of 40 ° C. or higher in the monomer mixture is 15 to 60%, preferably 20 to 50%. The compounding weight% of the ethyl acrylate monomer (B) is 20 to 70%, preferably 25 to 65%. (B)
If the compounding amount exceeds 70%, the melting point becomes too low, so that the extensibility to the skin deteriorates. If the compounding amount is 20% or less, the adhesion to the skin deteriorates, and the soft feeling of use is impaired. The blending percentage by weight of the polyfunctional vinyl monomer (C) can be increased or decreased in the range of 0 to 50% in accordance with required oil resistance, solvent resistance and heat resistance, but is preferably 10 to 30%.
When the blending percentage by weight of (C) exceeds 50%, the soft feeling of use is impaired. In the suspension polymerization, a (meth) acrylate monomer, an ethyl methacrylate monomer, a polyfunctional vinyl monomer, a dispersant, an oil-based radical polymerization initiator and water, if necessary, are charged into a polymerization vessel together with a polyfunctional vinyl monomer, and reacted under stirring. Allow the particles to form. By using a polyfunctional vinyl monomer, the heat resistance and the solvent resistance of the copolymer particles can be improved. Examples of the dispersant include gelatin, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, polyethylene glycol,
Water-soluble polymers such as polyoxyethylene-polyoxypropylene block copolymer, polyacrylamide, polyacrylic acid, polyacrylate, sodium alginate, and polyvinyl alcohol; inorganic substances such as tricalcium phosphate, titanium oxide, calcium carbonate, and silicon dioxide And the like. Of these dispersants, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, tricalcium phosphate, and the like are preferably used. One or more of these dispersants can be used. The amount of the dispersant used is, for example, 0.1 to 30% by weight, preferably 0.5 to 10% by weight, based on the whole monomer mixture. If necessary, a surfactant for stabilizing the dispersion of the monomer droplets (for example,
Anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate and nonionic surfactants), and an aqueous phase polymerization inhibitor such as sodium nitrite may be added. Further, the monomer component may be subjected to dispersion treatment by a stirring or dispersion means such as a homomixer in advance, and the resulting dispersion may be charged into a polymerization vessel.

Examples of oil-soluble radical polymerization initiators include organic peroxides such as benzoyl peroxide, o-methoxybenzoyl peroxide, o-chlorobenzoyl peroxide, lauroyl peroxide, cumene hydroperoxide; Examples include azo compounds such as' -azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvaleronitrile). Among these radical polymerization initiators, benzoyl peroxide, lauroyl peroxide, 2,2′-
Azobisisobutyronitrile is often used. One or two or more radical polymerization initiators can be used, and the amount used is about 0.01 to 5% by weight, preferably about 0.1 to 2% by weight, based on the whole monomer mixture. In the step of suspension polymerization of the monomer mixture to form acrylic polymer particles, prior to the start of the reaction, for example, the mixture is stirred using a dispersing means such as a homogenizer to adjust the monomer droplets to a desired size. preferable. It is desirable to select suspension polymerization conditions so that the particle diameter of the fine particles is in the range of 1 to 40 μm, and the average particle diameter is 4 to 20 μm. In addition, in order to ensure the heat resistance of the fine particles, it is desirable to select the type and the use ratio of each monomer so that the glass transition temperature of the copolymer from which the monomer can be obtained is 50 to 130 ° C. By collecting polymer fine particles from the dispersion liquid produced by suspension polymerization, powdery polymer fine particles can be obtained. The powdery polymer particles can be obtained by, for example, a method of dehydrating with a centrifugal separator and drying with a vacuum dryer or the like, or a method of spray drying. Cosmetics suitable for blending the obtained fine particles are makeup cosmetics and solid-liquid multi-layer cosmetics, and specifically,
Creams, face powder, eye shadow, lipstick,
Such as pre-shave lotion. The mixing ratio of the copolymer fine particles to the cosmetic varies depending on the kind of the cosmetic, but is 5 to 10% by weight for cream, 10 to 20% by weight for face powder, and 10 to 20% by weight for emulsified foundation and pre-shaved lotion. It is about 1 to 10% by weight.
Cosmetics also include fragrances, preservatives, colorants, thickeners, p
An H adjuster, an astringent and the like may be appropriately blended.

[0008]

EXAMPLES The present invention will be described in more detail below with reference to production examples, examples and test examples of acrylic copolymer fine particles, but the present invention is not limited thereto. Example 1 45 parts by weight of methyl methacrylate, 45 parts by weight of ethyl acrylate, ethylene glycol dimethacrylate 10
20 parts by weight of a 10% by weight aqueous solution of polyvinyl alcohol (PVA-217, manufactured by Kuraray Co., Ltd.) and 250 parts by weight of ion-exchanged water were added to a mixed solution of parts by weight and 0.5 parts by weight of lauroyl peroxide. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.),
A dispersion treatment was performed at 5,000 rpm for 20 minutes to prepare a monomer dispersion. The obtained monomer dispersion was charged into a polymerization vessel equipped with a stirrer and a reflux condenser, and the temperature was raised to 70 ° C. while stirring under a nitrogen stream to carry out polymerization for 3 hours. Dehydration of the resulting acrylate copolymer particle dispersion, washing, drying,
By sieving, 90 parts by weight of acrylic copolymer fine particles having a particle size of 2 to 25 μm were obtained. Its average particle size is 8.
It was 2 μm.

Example 2 An acrylic resin having an average particle diameter of 8.0 μm was prepared in the same manner as in Example 1 except that 30 parts by weight of methyl methacrylate, 30 parts by weight of ethyl acrylate and 40 parts by weight of ethylene glycol dimethacrylate were used as monomers. 89 parts by weight of copolymer fine particles were obtained.

Example 3 The procedure of Example 1 was repeated except that 30 parts by weight of ethyl methacrylate, 45 parts by weight of ethyl acrylate, 20 parts by weight of ethylene glycol dimethacrylate and 5 parts by weight of 2-hydroxyethyl methacrylate were used as monomers. Acrylic copolymer fine particles 8 having an average particle size of 8.0 μm
8 parts by weight were obtained.

Comparative Example 1 91 parts by weight of acrylic copolymer fine particles having an average particle diameter of 8.3 μm in the same manner as in Example 1 except that 95 parts by weight of methyl methacrylate and 5 parts by weight of ethylene glycol dimethacrylate were used as monomers. I got

Comparative Example 2 An average particle diameter of 8.3 μm was obtained in the same manner as in Example 1 except that 60 parts by weight of methyl methacrylate and 40 parts by weight of ethylene glycol dimethacrylate were used as monomers.
92 parts by weight of acrylic copolymer fine particles were obtained.

Test Example 1 The acrylic copolymer fine particles obtained in Examples 1 to 3 and Comparative Examples 1 and 2 and 12 nylon powder (average particle size of 8.
(0 μm), the extensibility, adhesion and feeling of use on the skin were very good: 4 points, good: 3 points, ordinary: 2 points, slightly Poor: 1 point, considerably bad: 0 points were scored, and the resin powder was evaluated based on the following criteria from the total score. 30 points or more A 20 points to 29 points B 10 points to 19 points C Less than 10 points D

Regarding the oil resistance of the resin powder, 2 g of the resin powder sample was dispersed in 10 ml of a liquid ultraviolet absorbent, and
It was heated at 00 ° C. for 3 hours and evaluated by the following cohesion of the resin powder. No cohesion A Little coagulation B Cohesion C Cohesion considerable D The above results are summarized in [Table 1].

[0015]

[Table 1] As is evident from Table 1, the acrylic copolymer fine particles of Examples 1 to 3 have better adhesion and feeling of use than the polymethyl methacrylate fine particles of Comparative Examples 1 and 2, and have a higher quality than 12 nylon powder. Also has excellent oil resistance at high temperatures.

Test Example 2 A powdery foundation (formulation 1) and a dual-use foundation (formulation 2) were prepared using the acrylic copolymer fine particles obtained in Examples 1 to 3 and Comparative Examples 1 and 2 and each resin powder of 12 nylon powder. ) Was prepared. Formulation 1 Powdery foundation Powder: Talc 20.3% Mica 35.0 Kaolin 5.0 Titanium dioxide 10.0 Titanium dioxide 3.0 Zinc stearate 1.0 Bengala 1.0 Yellow iron oxide 3.0 Black iron oxide 0.2 Resin powder 10.0 Binder: Squalane 6.0 Lanolin acetate 1.0 Octyldodecyl myristate 2.0 Neopentyl glycol diisooctanoate 2.0 Sorbitan monooleate 0.5 Others: Preservative, antioxidant appropriate amount Perfume appropriate amount

Formulation 2 Dual-use foundation Powder: Silicone treated talc 19.2% Silicone treated mica 40.0 Silicone treated titanium dioxide 15.0 Silicone treated ultrafine titanium dioxide 5.0 Silicone treated red iron oxide 1.0 Silicone treated yellow iron oxide 3.0 Silicone treated black iron oxide 0.2 Zinc stearate 0.1 Resin powder 2.0 Binder: Squalane 4.0 Solid paraffin 0.5 Dimethyl polysiloxane 4.0 Glycerin triisooctanoate 5.0 Octyl methoxycinnamate 1.0 Other: Preservative, antioxidant Appropriate amount Perfume Appropriate amount

[0018] Ten panelists scored and evaluated the foundations of formulas 1 and 2 on the same basis as the sensory test of test example 1. The results are summarized in [Table 2].

[Table 2] As shown in [Table 2], 12 nylon powder was formulated in Formula 1,
In both cases, the feeling of use was excellent. Examples 1 to 3 were almost as good as 12 nylon powder, whereas Comparative Examples 1 and 2 had poor feeling in use for both Formulations 1 and 2.

[0019]

The acrylic copolymer fine particles of the present invention, when blended in cosmetics, have good spreadability and adhesion to skin, have a soft feeling of use, do not cause secondary aggregation of the fine particles, and can be used at high temperatures. Has excellent oil resistance and is suitable as fine particles for cosmetics. Moreover, it can be manufactured at a much lower cost than nylon powder.

Continued on the front page (72) Inventor Hirotaka Sakai 960 Shimo-Kokura, Kashiwara-cho, Hikami-gun, Hyogo Prefecture Inside the Gantz Inc.Tanba Works (72) Inventor Rika Inaba Rika 960, Shimo-Ogura, Kashiwara-cho, Hikami District, Hyogo Prefecture Inside the Gantz Taniwa Works (72) Inventor Shunsaku Tanaka 960 Shimo-Ogura, Kashiwara-cho, Hikami-gun, Hyogo Gantz Chemical Co., Ltd.F-term (reference) 4C083 AB232 AB242 AB432 AB442 AC012 AC022 AC242 AC302 AC342 AC352 AC422 AC442 AD091 AD092 AD152 AD512 BB24 CC01 CC12 DD17 EE01 EE06 EE07 FF01 4J011 AA05 JA02 JA06 JA08 JA13 JB08 JB14

Claims (4)

[Claims] A glass transition temperature (T) of 15 to 60% by weight.
g) a monomer mixture containing (meth) acrylate monomer (A) having a temperature of 40 ° C. or more, 20 to 70% by weight of ethyl acrylate monomer (B), and 0 to 50% by weight of polyfunctional vinyl monomer (C). Acrylic copolymer fine particles for cosmetics obtained by polymerization. 2. The glass transition temperature (T) of an acrylic copolymer.
The acrylic copolymer fine particles for cosmetics according to claim 1, wherein g) is 50 to 130 ° C. 3. The acrylic copolymer fine particles for cosmetics according to claim 1, wherein the particle size of the fine particles of the copolymer is in the range of 1 to 40 μm, and the average particle size is 4 to 20 μm. 4. A cosmetic comprising the acrylic copolymer fine particles for cosmetic according to claim 1.